[arch-general] New install second drive issue

[pete]

Morning folks 

I have just done a complete new install on a new drive , That is all
working now fine .

My problem comes when trying to include another drive on the system ,
it just refuses to boot fully , I get a message unable to mount sda2 
now sda2 mounts  ,
/dev/sda2 on / type xfs (rw,relatime,attr2,inode64,noquota)

when just the one drive is in the system  but as soon as i connect it
refuses to to boot fully and drops out to an emergency shell that is
locked up solid i.

I have set the working drive in the bios this is an older motherboard
with an AMD Phenome quad core CPU .

 $ lsblk
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda      8:0    0  1.8T  0 disk 
├─sda1   8:1    0  300M  0 part /boot
├─sda2   8:2    0   40G  0 part /
├─sda3   8:3    0    4G  0 part [SWAP]
└─sda4   8:4    0  1.8T  0 part /home
sr0     11:0    1 1024M  0 rom  

the drive order in the bios is set correctly not that it makes much
difference these days  .

I am stuck right now i need to be able to include the old drive to
recover data from it  .

Any ideas  folks ..

Pete .